Downdraft-kiln



A. W. F. WEYERS,

DOWNDRAFI KILN.

APPLICATION FILED APII.24,AI920.

' Patented. May 24, 1921.

UNITED sraras PAr-snrorrics.

ALOYSIUS 'WILHELM'.USA FRANCISCUS VVEYERS, OF TILBURG, NE1HIJIRLIJANLDS.Y

DowNnRArr-KILN.

Specification of Letters Patent.

Application filed April 24, 1920. Serial No.v376,3413.

To all 'whom it may concern:

Be it known that I, ALoYsiUs WiLHnLMUs FRANcIsoUs l/Vnrnns, a subject of the Queen of the Netherlands, and residing at 31 Stationsstraat, Tilburg, the Netherlands, have invented certain new and useful Improvements in and Relating to DowndraftfKilns, of4 which the following is a specification.

This invention relates to down draft kilns suitable for use in the manufacture of bricks, tiles and analogous ware.

` The kilns referred to are often heated by a numberv of fires on stepped grates. In this system of kilns said fires receive underneath the grate airfor air and combustion gases from 'the adjacent oven chamber or section. If owing to low gradefuel being used the grate is choked by cliiiker, the air supply is cut off and combustion4 is entirely prevented. As a result the required tem perature will not be obtained and the burning process will be greatly extended. It is practically impossible to su'lliciently remove the clinker from the stepped grates when in use.

According to the present invention the stepped grates are replaced by producers,

the latter just as the stepped grates receiving the fuel through fire-holes provided thereabove. The air in the usual manner drawn in from the chambers to be cooled or the excess of air together with the coinbustion gases from a previously lired kiln passes past said producers and (or) partly through the same.

Tt is advantageous to provide above each producer or retort a guide to the effect that the air ascending past the producer will be forced to pass over the latter. As a result thereof said air ismixed with the gases ascending from the producer, in this manner a complete combustion being eifected. No matter how the producer works, as a furnace, a retort or even as a simple fuel trough containing cokes, the air will always find its way to effect the combustion adapted for the manner of firing.

Each producer is preferably provided with a furnace plate with ash-hole, or with only a few ash holes, it being possible to keep the latter open when in use by means of a fire-iron which is inserted through the fire-holes. An inconvenient entering of cold fresh airis not necessarily connected with said clearing of the ash-holes.

As the producers do not prevent the admission of air to'the produced gases, the combustion fin the producer will proceed even when the ash-hole (or ash-holes) is entirely choked up with clinker, in which case the producer acts as a retort; for the air can also pass past the producer and in this way enter the combustion space. On account of the free admission of air to the upper part of the combustion chamber, the

Patented May 24, 1921.

coal in the producer-retort can even oXidize, thus making room for the supply of new fuel. Toward the end of the firing period it is even desirable to remove the clinker only partly or not at all from the furnaceplate below the producer, in order to obtain thereby a still more uniform heat supply and in consequence thereof a more perfectk control of the temperature.

Generally taken the firing in an oven or kiln according to this invention can be bet ter'regul'ated than in the present kilns. The combustion is more complete, so that in a brick kiln a more uniform burning of the goods will be obtained. The kiln is especially adapted for the making of uniformly colored products, as a smokeless combustion can be obtained.

lty has previously been suggested to feed lfuel into a shaft at its lower end provided with an inclined tunnel and opening there* with into the adjacent chamber. Said shaft has, however, been made in the solid brick- Vwork and can easily become choked up. In

order to have the air nevertheless flow from one chamber into the other, separate air channels which can be shut off by a valve have been provided in the brickwork. It is clearly evident that in such a system the combustion cannot be regulated, underr certain circumstances combustion being entirely impossible, for the shafts cannot act as retort or producer and have their gases mixed with the air.

Reverberatory ovens or kilns with a flat grate and charging holes provided thereabove through which the grate may apparently be cleared are also known. It must be admitted, however, that said grate too can become choked up in which case a system of separate fines with valves is required Lso lthe carbon is still possible.

choking up of the holes 7 must not neces-Y to provide a passage for the air. Kilns of this type are even more liable to give trouble when Vin use than ovens with stepped grates.

0n the'accompanying drawing the invention is illustrated by way of example.

Figure 1 is a vertical section on the line C D of Fig. 2 of tliekfiring chamber with producers according to the present invention. 1 l i Fig. 2 is a vertical section perpendicular to the cross section according to Fig-1 and on the line A B in said figure. The chambers?) contain the goods to be burned, e. g. bricks g the-combustion gases are introduced into the upper parts of said chambers through the iiame holes 4 defined between lthe baffles 4a. The fuel is fired in the producei's 5; it receives air from the ash chute @through the slagor ash-hole 7 and the side-holes 8, whereas the gases ascending from the producers are burned by means of air (or combustion gases mixed withf an A excess of air) passing through'the openings 9;V Thispre-heated air is admitted through the iues 10 opening into the adyacent'oven chamber.

ltappears from Fig. 1 that the air (or the ygas mixture with excess of air) :sup-

plied through the fluesl() is divided and enters partly as primary combustion air Vinto each producer, the remaining part reaching the producer gas as secondary vvcombustion air after flowing past the producers. In case the holes 7 become choked up and even when the holes 8 are also choked up,still a suicient combustion of the gases can takel place andV oxidizing of However, a

sarily take place for by means of a nre-iron inserted through the fire-hole 11 saidV holes 7 can be reached and cleared.

1n the wall between the producer space and the oven chamber removable fireproof mold bricks 12 are placed which can be removed foi' inspecting the producer or for the purpose of renewing the producer walls, when the concerned chamber of the oven is cooled down.V i

In case fuel containing a high percentage of ash is used, in the ash chute Va valve may be provided, through which the ash-holes below the producers are cut off from the air supply, it in this manner being possible to remove the ash without admitting cold air. Usually such a cut-olf valve, will, however, be superfluous. Y

From thel foregoing it appears thatan oven or kiln provided with the described producers has a greater safety of working than an oven with stepped 4grates, while moreover, as already mentionedv in the introduction, the temperature can be regulated more exactly. It is further a not to Ybe underrated advantage that the oven works with a long flame, on account thereof a more uniform temperature being obtained in the kiln. rlhe dierence with the working` with stepped grates is obvious especially in the kiln heated to the highest temperature, for on said grates Vthe fuel must be supplied repeatedly and in small quantities, as there an excess of air preheated to a very vhigh degree is used. This will result'in arepeated violent blazing up of the flame rand a corresponding change of the temperature. With a producer-oven according to thepresent invention smokeless ring. is secured, an economy of fuel in comparison to other ovens being obtained thereby.

1t is self-evident that the present invention is applicable Ynot only to chamber ovens or kilns, but also to Hoffman kilns.

Having now particularly described and ascertained the nature of my said invention and in'what manner the same isQtobe perf formed, I declare that what 1 claim is 1. 1n a kiln, independent adjoining apartments with intervening walls between them, passages in said walls, re chambers Varranged in thepapartments having air admitting vopenings in their lower portionsand open upper ends,- said fire chambers being arranged in spaced relation to provide vertical air passages therebetween.

2. 1n aV kiln, independent adjoining apartments with intervening walls betweenthem,

passages in said walls, fire chambers arranged inthe apartments having air admitting Vopenings in their lower portions and open upper ends, said fire chambers being arranged in spaced relation to provide vertical air.V passages therebetween and bames for deflecting air across the open tops of the fire chambers.

3. In akiln independentadjoiningapartvments with intervening walls between them,

passages in said walls, fire chambers arranged in the apartments' having air admitting openings and vash-holes in their lower portions and provided with open upper air passages arranged to deflect air across the open 'tops ofthe fire chambers.4

5. In a kiln, independent adjoining apartments with intervening walls between them, passages in said walls, re chambers arranged in the apartments having air admitting openings in their lower portions and open upper ends, said re chambers be ing arranged in spaced relation to provide vertical air passages therebetween, and baffles arranged above the vertical air passages each provided with oppositely inclined faces disposed to deflect air laterally in opposite directions across the upper l() open ends of the two adjacent fire chambers.

In testimony whereof I affix my signature.

ALOYSIUS WILHELMUS FRANCISCUS WEYERS. 

